Statistical tracking for global server load balancing

• US 8,949,850 B2
• Filed: 05/05/2006
• Issued: 02/03/2015
• Est. Priority Date: 08/01/2002
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: Joshi, Prajakta Suresh, Kommula, Sunanda Lakshmi
• Primary Examiner(s): KAWSAR, ABDULLAH AL
• Application Number:
  US11/429,177
• Publication Number:
  US 20100223621A1
• Time in Patent Office: 3,196 Days
• Field of Search: 718/105
• US Class Current: 718/105
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1021 based on client or server locations
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs

Abstract

Server load-balancing operation-related data, such as data associated with a system configured for global server load balancing (GSLB) that orders IP addresses into a list based on a set of performance metrics, is tracked. Such operation-related data includes inbound source IP addresses (e.g., the address of the originator of a DNS request), the requested host and zone, identification of the selected “best” IP addresses resulting from application of a GSLB algorithm and the selection metric used to decide on an IP address as the “best” one. Furthermore, the data includes a count of the selected “best” IP addresses selected via application of the GSLB algorithm, and for each of these IP addresses, the list of deciding performance metrics, along with a count of the number of times each of these metrics in the list was used as a deciding factor in selection of this IP address as the best one. This tracking feature allows better understanding of GSLB policy decisions (such as those associated with performance, maintenance, and troubleshooting) and intelligent deployment of large-scale resilient GSLB networks.

Claims

1. A computerized method performed by a module on a network device, the method comprising:

arranging, by the network device network addresses into an ordered list based on a set of different types of performance metrics in response to a request for a network address by a query;

respectively incrementing, by the network device a first plurality of counters to count a number of times that each different type of performance metric of the set is used to determine a best network address among the ordered list of network addresses for selection in response to the query, wherein each counter of the first plurality of counters is associated with a different performance metric of the set of different types of performance metrics; and

comparing the counts associated with each different type of performance metric, the comparison indicating a status of a subset of the network addresses.

2. The computerized method of claim 1, further comprising determining the best network address from a plurality of the network addresses contained in a domain name system (DNS) response in reply to a DNS query.

3. The computerized method of claim 2, further comprising for a plurality of additional queries, respectively incrementing, by the network device, a second plurality of counters to count a number of times that each address among the ordered list of network addresses is selected as a best network address, wherein each counter of the second plurality of counters is associated with one of the network addresses.

4. The computerized method of claim 2, further comprising:

recording, from the DNS response in reply to the DNS query, an address of a source of the DNS query; and

recording, from the DNS response in reply to the DNS query, a requested host and zone.

5. The computerized method of claim 1, wherein arranging network addresses into an ordered list comprises:

arranging virtual network addresses, respectively located at site switches that communicate with the network device, into the ordered list.

6. The computerized method of claim 1, wherein the network device is arranged as a proxy to an authoritative DNS server to receive the DNS response from the authoritative DNS server.

7. The computerized method of claim 1, further comprising receiving instructions to enable or disable, for each different type of performance metric, the count of the number of times that each different type of performance metric of the set is used to determine the best network address.

8. An article of manufacture, comprising:

a non-transitory machine-readable medium comprising machine-readable instructions stored thereon to when executed performs the steps of;

arranging virtual network addresses, each associated with at least one host server, into an ordered list based on a set of different types of performance metrics in response to a request for a virtual network address by a query;

incrementing a first plurality of counters to count a number of times that each different type of performance metric of the set is used to determine a best virtual network address among the ordered list of virtual network addresses for selection in response to the query, wherein each counter of the first plurality of counters is associated with a different performance metric of the set of different types of performance metrics; and

comparing the counts associated with each different type of performance metric, the comparison indicating a status of a subset of the virtual network addresses.

9. The article of manufacture of claim 8, wherein the best virtual network address is selected in response to a query.

10. The article of manufacture of claim 9, wherein the non-transitory machine-readable medium further comprises machine-readable instructions stored thereon to:

increment a second plurality of counters, for a plurality of additional queries, to count a number of times that each virtual network address among the ordered list of virtual network addresses is selected as a best virtual network address, wherein each counter of the second plurality of counters is associated with one of the virtual network addresses.

11. The article of manufacture of claim 9, wherein the non-transitory machine-readable medium further comprises machine-readable instructions stored thereon to:

obtain, from a reply to the query, a source address of the query.

12. The article of manufacture of claim 9, wherein the non-transitory machine-readable medium further comprises machine-readable instructions stored thereon to:

obtain, from a reply to the query, a requested host and zone.

13. The article of manufacture of claim 8, wherein the non-transitory machine-readable medium further comprises machine-readable instructions stored thereon to:

selectively enable or disable, for each different type of performance metric, the count of number of times that each different type of performance metric of the set is decisive in selection of one of the virtual network addresses as the best network address.

14. The article of manufacture of claim 8, wherein the non-transitory machine-readable medium further comprises machine-readable instructions stored thereon to:

communicate, to an external device, the counts of the number of times that each different type of performance metric of the set is decisive in selection of one of the virtual network addresses as the best network address.

15. A network connected device comprising:

a module to arrange network addresses into an ordered list based on a set of different types of performance metrics in response to a request for a network address by a query;

a plurality of metric counters to count a number of times that each different type of performance metric in the set of different types of performance metrics is used as a deciding factor in selection of a best network address among the ordered list of network addresses in response to the query, wherein each metric counter of the plurality of metric counters is associated with a different performance metric of the set of different types of performance metrics;

comparing the counts associated with each different type of performance metric, the comparison indicating a status of a subset of the plurality of network addresses; and

a non-transitory storage medium to store an identification of the best network address and an identification of which metric was used to select the best network address.

16. The network connected device of claim 15, wherein the network connected device is arranged as a proxy to an authoritative domain name system (DNS) server to receive a DNS response, comprising a list of addresses from which the best address is selected, from the authoritative DNS server.

17. The network connected device of claim 16, wherein the ordered list includes the best network address at the top of the list.

18. The network connected device of claim 15, wherein the network connected device further comprises a second plurality of counters to count a number of times that each network address of the plurality of network addresses is selected as the best network address, wherein each counter of the second plurality of counters is associated with one of the network addresses.

19. The network connected device of claim 15, wherein each of the plurality of metric counters, can be selectively enabled or disabled.

20. The network connected device of claim 15, wherein the network connected device is arranged to provide, to a syslog server, a count of the number of times that each different type of metric in the set of different types of performance metrics is used as the deciding factor.